Wire twisting tool



1960 c. E. CHAPPEL ET AL ,96

WIRE TWISTING TOOL Filed April 11, 1956 -MWNNN w p mNT S C. EUGENE CHAP ATTORNEYS B LLIAM A BARNES fil a d TWISTING TOOL C. Eugene Chappel, Whitesboro, and William A. Barnes,

Utica, N.Y., assignors, by mesne assignments, to Kelsey- Hayes Company, Detroit, Mich., a corporation of Delaware Filed Apr. 11, 1956, Ser. No. 577,537

Claims. (Cl. 140-119) This invention relates to tooling for twisting two wires together for such purposes as twisting the bolt retaining wires of aircraft engines.

The principal application of the praent invention is in the aircraft engine industry. The bolts of such engines are protected against becoming loosened, and indicate their looseness when loosening does occur by the provision of wires threaded through each bolt head. The wires are twisted between the bolts to produce a tight holding condition.

There are numerous devices available to do such twisting. The latest such device is shown in United States Patent 2,737,983. Some such devices provide a degree of advantage over pliers, but none have provided all desired qualifications. The present invention has proven to be a practical solution to the problem of getting such wires tightly twisted up to the bolt head and doing the job expeditiously.

Therefore, an object of this invention is to provide a wire twisting tool which produces a twisting action and a tensioning action simultaneously.

Another object of this invention is to provide a wire twisting tool which produces a rotary twist drive as the tool is pulled by a reciprocable drive impeller.

Another object of this invention is to provide a twist screw with a drive impeller carried thereby to provide a rotating drive to a wire carrying work head.

Still another object of this invention is to provide a releasable cam follower acting between the twist screw and drive impeller, the cam follower being operative in only one direction of movement of the drive impeller to thereby produce a drive action and rotary drive simultaneously and only as a pulling force is applied.

Yet another object of this invention is to provide a hand grip bearing for the tool, which hand grip bearing provides free rotational support of the drive screw in a drive direction and resists reversal of the screw rotational direction.

And another object of this invention is to provide a wire gripping head having a cam clamping action which allows wire to slip through the wire grip but causes a tendency to increase the wire grip as the wire is pulled therethrough.

And yet another object of this invention is to provide such a head with a wire cutting device coupled with the cam clamping action, the cutting device being actuated by a hand lever movement in a first direction, and the clamping action caused by movement of the hand lever in the opposite direction.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

Figure 1 is an elevational view of the preferred embodiment of the tool, with the hand grip bearing and drive impeller illustrated in section;

Figure 2 is a second type of wire holding head which 27,954,069 Patented Dec. 13, 1960 may be employed in place of that illustrated in Figure 1;

Figure 3 is a sectional view taken along line 33 of Figure 1;

Figure 4 is a sectional view taken along line 44 of Figure 1;

Figure 5 is a face view of the drive collar carried by the drive impeller as viewed from the enlarged entrance or ball carrying socket of the passageway therethrough;

Figure 6 is an enlarged fragmentary portion of the drive impeller and twist screw illustrating the cam follower ball engaged in a drive transfer action; and,

Figure 7 is a view of the escapement action of the ball cam follower mechanism as the drive impeller is indixed to a forward starting position.

The preferred embodiment of the invention as here illustrated is intended principally for the provision of twisting bolt retaining wires between the bolts of an aircraft engine. The use of such retaining wires and their purpose is well understood. The embodiment of Figure 1 comprises generally a head 10 rotatably driven by a longitudinally extending spiralled cam 11 which is in the true sense a twist screw. The tool is intended for hand operation, and is therefore provided with a bearing hand grip 12 which not only provides a convenient supporting grip for the tool but also prevents rotation of the head 10 in a reverse direction, as will be more fully explained hereinafter.

One of the desirable results of use of the tool of this invention is that the wires being twisted are at the same time placed under a tensile drawing force in order to produce a tight wire twist without any possibility of slack in the wire. Accordingly, the rotary drive force which is applied to the twist screw cam 11. is applied by pulling the tool away from the work head. This driving by tensile pull is accomplished by means of a drive impeller .20 which is mounted for longitudinal reciprocable movement with respect to the cam 11 and is provided with cam follower means having a first engaged condition locked into the twist screw cam when the impeller 20 moves to the right in Figure 1, as indicated by the arrow in Figure 5, and is released when the drive impeller 20 is moved to the left in Figure 1, as indicated by the arrow in Figure 6.

To better understand the operation and function of this preferred embodiment of the invention, the construction and operation of the drive impeller 20 will be explained first. The illustrated embodiment of the drive impeller comprises a hand grip body 21 which has been made of a synthetic material for appearance. Any suitable material, even wood, will be satisfactory. A bushing 22 has been provided at one end of the body 21 to define a longitudinal passage for the cam 11 which will resist abrasion of the hand grip material. At the opposite end from the bushing 22, a collar 23 is nonrotatively secured into the body 21. To aid in holding the collar 23, a spring clip 24 is positioned in the end of the body 21. The collar 23 has a longitudinal passageway 25 therethrough to accept the twist screw cam 11. This passageway 25 has a flared entrance 26 facing the bushing 22. The flared entrance 26 is in fact the forward portion of the passage 25 in view of the fact that the drive impeller is operative to impart driving rotation to the twist screw cam 11 upon movement of the drive impeller 20 to the right, or in a direction away from the head 10.

The flared entrance 26 is fluted to provide a plurality of ball raceways 27. One ball 28 is positioned in each such raceway and is urged into the raceway by means of a rider 2? urged by a coiled spring 30.

Accordingly, when the drive impeller 20 is pulled away from the head 10, the balls 28 ride the respective raceways 27, and accordingly are wedged between the raceways 27 and the surface of the twist screw cam 11. The individual balls will thus seat themselves into an individual surface track of the cam. Accordingly, as the drive impeller 20 is pulled away from the head 10, a twisting drive action will be imparted from the twist screw cam 11 through the balls 28 to the collar 23. Resistance to rotation of the drive impeller 20, as would be accomplished by the hand grip of the operator, will accordingly reverse this thrust and cause the twist screw cam 11 to rotate. Accordingly, a firm drawing of the drive impeller 20 away from the head will impart a driving rotational force to the cam '11 and the head it Reversal of the direction of movement of the drive impeller to index the drive impeller for a new stroke, will cause a release of the interconnection between the twist screw cam 11 and the drive impeller 26. Such release is caused by the reaction forces of the balls 28. As the drive impeller 29 is moved toward the head 10 the balls 28 will tend to ride over the confining side edges of their individual cam tracks on the surface of the twist screw cam 11 and consequently a force will result tending to dislodge the balls 128 from their individual raceways 27. The resistance of spring 3% is suflicient to maintain the balls seated at the bottom of the raceways 27, and consequently the rider 2) will retract and allow the balls to ride over the individual track surfaces in the manner indicated by the dotted outline of the balls 28 in Figure 6. Consequently, all cam rotational drive force is lost between the drive impeller 20 and the twist screw cam 11 upon indexing of the drive impeller toward the head 10. Therefore, rotational driving force is imparted to the spiralled cam 11 only when the drive impeller is drawn away from the head It). Consequently, wires being twisted by this improved tool will be placed under tension simultaneously with a rotational twisting drive to produce a tight twisted wire condition.

Such tightly twisted wire condition is extremely desirable in the securing of bolts in an aircraft engine. If such tensioning were not provided simultaneously with the twisting, and such tensioning is not available in prior art devices generally, -a loosely wound wire condition can result unless the operator is highly skilled in producing the tensioning as he causes the wires to be twisted. This invention eliminates the need for operator skill and assures a proper wire tensioning as the twist is accomplished.

Being a hand tool, it is preferable that a second hand grip support be provided other than the grip provided by holding the drive impeller 20. According to this invention, a hand grip is provided by the grip 12, but in addition provides a further function in preventing reverse rotation of the head 10 under the drive force of the twisted workpiece wires tending to unwind after the drive impeller 29 has reached the end of its drive stroke. Such a tendency to unwind, if allowed to go unchecked, will result in a loose area of winding which could result in a defective wire twisting job, and certainly will result in annoyance to the operator. Accordingly, the bearing hand grip 12 in addition to being a support for the tool, also is provided with an overriding clutch 15. The construction of the overriding clutch 15 in and of itself is not particularly novel. The construction is illustrated in Figure 4 and will at once be recognized as a type of structure which wedges a ball between the cooperating parts upon movement in the direction to be opposed, and allows the ball to ride free upon rotation of the respective members in a proper direction.

In addition, the construction of the bearing hand grip 1 2 includes a bushing 13 in order to permit the use of decorative or softer materials for the body of the grip and yet prevent abrasive wear between the body of the grip and the surface of the spiralled cam 11. At the opposite end of the grip is provided a sealed bearing 14 which provides a journalled bearing support of the head It and seals dirt out of the interior of the hand grip 12. A spring clip 16 is provided to hold the bearing 14 and the overriding clutch 15 within the hand grip. A second spring clip 17 at the opposite end of the bearing and clutch assembly holds the hand grip 12 and the head 10 against relative longitudinal movement while permitting free rotational relative movement.

The preferred and alternate constructions of the head 10 are set forth in Figures 1 and 2. In Figure 1 the head 10 is illustrated as a longitudinal member terminating at the forward portion in two opposed wire supporting anvil ribs 35 and 36. These ribs, in Figure 1, are illustrated as extending at a converging angle with respect to the longitudinal rotational axis of the head 10. Cam formed clamp levers 37 and 38 are pivotally mounted by a pivot pin 39 and urged into a wire retaining relationship with the anvil ribs 35 and 36 by means of a spring 45].

The cam formation of the levers 37 and 33 is formed to cause a grip action as the levers swing apart around the rear of the pivot pin 39 with respect to the forward end of the tool. Accordingly, work wires 41 and 42, when placed in supportingcontact upon the anvil ribs 35 and 36, are sungly held by the movement of the cam clamp levers 37 and 38 toward the anvil ribs. However, in addition to a mere holding by means of the spring action 40, the fact that thecam levers rotate around the pivot pin to the rear thereof provides a tendency to grip the wires more tightly as the wires are drawn between the cam levers and anvil ribs is not sufiicient to hold the wires immobile against withdrawal, or otherwise a continual twist to the wires could not be accomplished. It is intended that the wires feed through this grip. However, by providing the cam levers to operate to the rear of the pivot 39, the tendency is to draw the grip tighter rather than to cause a tendency to loosen the grip. Accordingly, a snug grip is assured regardless of the actual strength of the spring 40.

The cam gripping of the wire is not new. This is used in wire stretchers for fences and for linemans comalongs. However, it is believed that an initial spring urge is new, particularly in the use as employed in this invention. The anvil ribs 35 and 36 preferably do not extend at a true 90 degree angle with respect to a lateral plane between them, but rather are tipped back about 5 degrees, to extend at an degree angle. Thus, the wires tend to cling and resist dropping off the edge of the ribs.

The head structure illustrated in Figure 2 is to be preferred in several respects. It has been found that a single cam gripping action is sufficient to cause proper wire gripping, and accordingly this head member is provided with only one anvil rib 43 and one cam clamp lever 45. In addition, however, the stationary member is provided with a shear edge 44 and the cam clamp lever 4-5 with a shear edge 46. Accordingly, when the lever 45 is pivoted to a wire releasing position against the urge of its spring, a shear action is provided which may be employed to cut the work wires. Therefore, the work wires may be quickly severed without necessity of laying this wire twister tool down and picking up a cutting instrument. Both wires are carried between the grip surface 47 of lever 45 and the anvil rib 43, and once again, the action of the cam lever is to resist withdrawal of the wires by reason of a cam formation operating to the rear of the pivot which therefore tends to tighten upon the wires as they are withdrawn from. the tool through the gripping action.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example, and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A rotatable drive tool, comprising, a longitudinally spiralled cam twist screw, a work head carried by said cam twist screw, a bearing hand grip, said cam twist screw being journalled in said bearing hand grip for free rotation in a drive direction, means preventing relative longitudinal movement of the cam twist screw and the hand grip, a drive impeller carried by said cam twist screw, said drive impeller being mounted for longitudinal reciprocable movement with respect to the cam twist screw and said hand grip, said drive impeller having a guide collar with a longitudinal passageway therethrough, said cam twist screw passing through said passageway, said passageway having a flared entrance portion, at least one ball raceway extending longitudinally of said passageway along said flared entrance portion, a ball in said raceway, resilient means urging said ball along said raceway into the passageway, the ball and collar raceway thereby serving as a cam follower means having an engaged condition locking the drive impeller and cam twist screw together upon movement of the collar in the direction of the said flared entrance portion for conversion of relative longitudinal movement of the cam twist screw and drive impeller into relative rotary movement, the ball cam follower being selfdisengaging upon movement of the drive impeller in the opposite direction, whereby the drive impeller may be driven longitudinally in a first direction while held against rotation to thereby impart a rotary drive to said cam twist screw and the work head, and may be reversed with no rotational drive tendency.

2. A rotatable drive tool, comprising, a longitudinally spiralled cam twist screw, a work head carried by said cam twist screw, a bearing hand grip, said cam twist screw being journalled in said hand grip, means preventing relative longitudinal movement of the cam twist screw and the hand grip, and overriding clutch means locking said cam twist screw and bearing against relative rotation in one direction and permitting free relative rotation in the other direction, a drive impeller carried by said cam twist screw, said drive impeller being mounted for longitudinal reciprocable movement with respect to the cam twist screw and said hand grip, said drive impeller having a guide collar with a longitudinal passageway therethrough, said cam twist screw passing through said passageway, said passageway having a flared entrance portion, at least one ball raceway extending longitudinally of said passageway along said flared entrance portion, a ball in said raceway, resilient means urging said ball along said raceway into the passageway, the ball and collar raceway thereby serving as a cam follower means having an engaged condition locking the drive impeller and cam twist screw together upon movement of the collar in the direction of said flared entrance portion for conversion of relative longitudinal movement of the cam twist screw and drive impeller into relative rotary movement, the ball cam follower being self-disengaging upon movement of the drive impeller in the opposite direction, whereby the drive impeller may be driven longitudinally in a first direction while held against rotation to thereby impart a rotary drive to said cam twist screw and the work head, and may be reversed with no rotational drive tendency.

3. A rotatable drive tool comprising, a longitudinally spiralled surface on a rotatable shaft, a work performing head carried by said shaft, a drive impeller carried by said shaft, said drive impeller being mounted for longitudinal reciprocable movement with respect to the shaft, said drive impeller having an interior surface defining a ball raceway extending in an acute angular relationship with respect to the surface of said associated shaft, a ball in said raceway, said raceway defining a pathway of confined movement for said ball between a first and second position, said pathway lying substantially in the plane of the longitudinal axis of the shaft, at said first position said raceway providing less space than the diameter of the ball and providing a space in conjunction with a spiral of said shaft to accept said ball, whereby driving engagement between said shaft and said impeller is effected, at

said second position said raceway providing room for said ball to move away from said shaft, resilient means urging said ball along said raceway to said first position, the ball and raceway thereby serving as a cam follower means having an engaged condition locking the drive impeller and shaft together upon movement of the drive impeller in the direction of the outward extent of said angular raceway for conversion of relative longitudinal movement of the shaft and drive impeller into relative rotary movement, the ball being self-disengaging upon movement into said second position by movement of the drive impeller in the opposite direction, whereby said driving engagement is broken.

4. In a rotatable drive tool comprising, a longitudinally spiralled surface on a rotatable shaft, said raceway defining a pathway of confined movement for said ball between a first and second position, said pathway lying substantially in the plane of the longitudinal axis of the shaft, at said first position said raceway providing less space than the diameter of the ball and providing a space in conjunction with a spiral of said shaft to accept said ball whereby driving engagement between said shaft and said impeller is effected, at said second position said raceway providing room for said ball to move away from said shaft, a drive impeller carried by said shaft, a driving ball carried in said angular raceway within said drive impeller, said raceway defining a pathway of confined movement for said ball between a first and second position, said pathway lying substantially in the plane of the longitudinal axis of the shaft, at said first position said raceway providing less space than the diameter of the ball and providing a space in conjunction with a spiral of said shaft to accept said ball, at said second position said raceway providing room for said ball to move away from said shaft, and resilient means urging said ball to said first position, the ball being self-disengaging upon movement into said second position by movement of the drive impeller, in said second position said driving engagement is broken.

5. A speed plier for rapid axial rotation, comprising, a workpiece grasping head, a spiral grooved cam shaft, said shaft lying along and defining a desired axis of rotation, a cam follower member, said follower member carrying ball race means surrounding said shaft, said race means defining a ball path converging upon said shaft and ending in a first position wherein a ball therein is confined against further movement along the shaft, at least one ball carried by said race, resilient means urging said ball to said first position, said race diverging to an extent whereby said ball is unconfined between the race and shaft and is therefore free to jump over the apices of the spirals of the shaft, said ball and race thereby acting as a self-actuating clutch forcing cam and cam follower engagement upon relative longitudinal movement of shaft and follower in one direction only, said cam shaft and follower orientated to institute such engagement only upon a manual pulling force away from said head.

References Cited in the file of this patent UNITED STATES PATENTS 779,221 Kennard June 3, 1905 924,372 Peck June 8, 1909 1,209,434 Hayden Dec. 19, 1916 1,460,201 Leopold June 26, 1923 1,678,551 Bonos July 24, 1928 2,116,659 Harshberger May 10, 1938 2,490,449 Lynch Dec. 6, 1949 2,709,725 Bieber et al. May 31, 1955 2,737,983 Pray Mar. 13, 1956 FOREIGN PATENTS 622,696 Great Britain May 5, 1949 

